_In order to constitute a case there must be a change of form._--This statement is a matter of definition. A second question, however, arises out of it; _viz._, whether _every change of form constitute a case_? In the Greek language there are the words [Greek: erin] (_erin_), and [Greek: erida] (_erida_). Unlike the words _father_ and _father's_ these two words have precisely the same meaning. Each is called an accusative; and each, {236} consequently, is said to be in the same case with the other. This indicates the statement, that in order to constitute a case there must be not _only a change of form_, _but also a change of meaning_. Whether such a limitation of the word be convenient, is a question for the general grammarian. At present we merely state that there _is no change of case unless there be a change of form_. Hence, in respect to the word _patribus_ (and others like it), which is sometimes translated _from fathers_, and at other times _to fathers_, we must say, not that in the one case the word is ablative and in the other dative, but that a certain case is used with a certain latitude of meaning. This remark bears on the word _her_ in English. In _her book_ the sense is that of the case currently called genitive. In _it moved her_, the sense is that of the case currently called the accusative. If we adhere, however, to what we have laid down, we must take exceptions to this mode of speaking. It is not that out of the single form _her_ we can get two cases, but that a certain form has two powers; one that of the Latin genitive, and another that of the Latin accusative. s. 290. This leads to an interesting question, _viz._, what notions are sufficiently allied to be expressed _by_ the same form, and _in_ the same case? The word _her_, in its two senses, may, perhaps, be dealt with as a single case, because the notions conveyed by the genitive and accusative are, perhaps, sufficiently allied to be expressed by the same word. Are the notions, however, _of a mistress_, and _mistresses_, so allied? I think not; and yet in the Latin language the same form, _dominae_, expresses both. Of _dominae_=_of a mistress_, and of _dominae_=_mistresses_, we cannot say that there is one and the same case with a latitude of meaning. The words were, perhaps, once different. And this leads to the distinction between _a real and an accidental identity of form_. In the language of the Anglo-Saxons the genitive cases of the words _smith_ (_smidh_), _end_ (_ende_), and _day_ (_daeg_), were, respectively, _smithes_ (_smidhes_), _endes_, and _dayes_ (_daeges_); whilst the nominative plurals were, respectively, _smithas_ (_smidhas_), _endas_, and _dayas_ (_daegas_). A process of change took place, by which the vowel of the last syllable in each {237} word was ejected. The result was, that the forms of the genitive singular and the nominative plural, originally different, became one and the same; so that the identity of the two cases is an accident.